# LED Christmas Lights: A Voltage Guide

Light-emitting diodes (LEDs) are becoming more and more common nowadays, and are even used to make LED Christmas lights. In earlier times, LEDs produced only red light that had a low intensity, but today they are more powerful and vary in wavelength and brightness For example, LEDs are found in ultraviolet, infrared and visible light.

## Connecting the LED Lights

Be very careful when you connect your LED Christmas lights to a power supply, because if the power supply is too strong, the light may be destroyed and you cannot use them again. The lights may break because they take too much power. You must make sure that there is a resistor in the circuit to help control the voltage.

## Following Ohm’s Law

Keep in mind that you should follow Ohm’s Law to check the circuit of your Christmas lights and see that everything is working properly. According to Ohm’s Law, the voltage is the product of the resistor and the current, so V = IR; the letter V represents the voltage, I the current and R represents the resistor. In most cases, these LED Christmas lights are valued to run on a 0.25-amp electric current and are usually controlled with a 12-volt power source.

## Giving an Example with White LED Lights

An ordinary white LED light produces a fall in voltage that amounts to about 3.6 volts. For this reason, if you have a light running on a 12-volt power supply, you need a series of about three LED lights running fully. In this case, the drop is 10.8 volts because each one of the three lights produces a voltage fall of 3.6 volts.

You now need to subtract the 10.8 volts from the 12 volts. The result, 1.2 volts, is therefore the extra voltage drop required for the LED Christmas light circuit. On the other hand, to calculate the resistor’s wattage, you have to multiply the 1.2 volts by 0.25 amps. Since the answer is going to be 0.03 watts, a ¼ watt resistor would be enough.

Make sure that you control the voltage and the electric current running through the circuit of your LED Christmas lights. If you fail to regulate the voltage properly, you risk blowing out the lights permanently. In case you are not sure, it is highly recommended that you check the calculations again by using a LED resistor calculator.

## Safety of LED Christmas Lights

Once you have the voltage in control, you can put your mind at rest that the circuit of your LED Christmas lights is safe. LED lights have many advantages. They do not become hot when they are on. In fact, if you touch one of them, you will not burn your hand. LED Christmas lights are considered the most long-lasting lights of all, and there will be no hazard in your home, such as the Christmas tree catching on fire.

LED Christmas lights save a lot of power because they do not use much. For example, a 2-meter string of about 70 LED lights uses only four watts altogether, while on the other hand, one normal Christmas light uses 5 watts all by itself.